Sacroiliac joint fixation system

ABSTRACT

A sacroiliac joint fixation fusion system that provides a method of fixation and fusion of the sacroiliac joint and a sacroiliac joint implant which upon placement within the articular region of the sacroiliac joint facilitates stability and fusion of the sacroiliac joint.

This Application is a continuation of U.S. patent application Ser. No.12/998,712, filed May 23, 2011, which is the National Stage ofInternational Patent Cooperation Treaty Patent Application No.PCT/US11/00070, filed Jan. 13, 2011, which claims the benefit of U.S.Provisional Patent Application No. 61/335,947, filed Jan. 13, 2010, eachhereby incorporated by reference herein.

I. TECHNICAL FIELD

Generally, a sacroiliac joint fixation fusion system that provides amethod of fixation and fusion of the sacroiliac joint and a sacroiliacjoint implant which upon placement within the articular space of thesacroiliac joint facilitates stability and fusion of the sacroiliacjoint.

II. BACKGROUND

The sacroiliac joint is the joint between the sacrum and the ilium ofthe pelvis, which are joined by ligaments. In humans, the sacrumsupports the spine and is supported in turn by an ilium on each side.The sacroiliac joint is a synovial joint with articular cartilage andirregular elevations and depressions that produce interlocking of thetwo bones.

Pain associated with the sacroiliac joint can be caused by traumaticfracture dislocation of the pelvis, degenerative arthritis, sacroiliitisan inflammation or degenerative condition of the sacroiliac joint,osteitis condensans ilii, or other degenerative conditions of thesacroiliac joint. Currently, sacroiliac joint fusion is most commonlyadvocated as a surgical treatment for these conditions. Fusion of thesacroiliac joint can be accomplished by several different conventionalmethods encompassing an anterior approach, a posterior approach, and alateral approach with or without percutaneous screw or other typeimplant fixation. However, while each of these methods have beenutilized for fixation and fusion of the sacroiliac joint over the pastseveral decades, substantial problems with respect to the fixation andfusion of the sacroiliac joint remain unresolved.

A significant problem with certain conventional methods for fixation andfusion of the sacroiliac joint including the anterior approach,posterior approach, or lateral approach may be that the surgeon has tomake a substantial incision in the skin and tissues for direct access tothe sacroiliac joint involved. These invasive approaches allow thesacroiliac joint to be seen and touched directly by the surgeon. Oftenreferred to as an “open surgery”, these procedures have the attendantdisadvantages of requiring general anesthesia and can involve increasedoperative time, hospitalization, pain, and recovery time due to theextensive soft tissue damage resulting from the open surgery. A dangerto open surgery using the anterior approach can be damage to the L5nerve root which lies approximately two centimeters medial to thesacroiliac joint or damage to the major blood vessels. Additionally,these procedures typically involve fixation of the sacroiliac joint(immobilization of the articular surfaces of the sacroiliac joint inrelation to one another) by placement of one or more screws or byplacement of one or more trans-sacroiliac implants (as shown by thenon-limiting example of FIG. 1) or by placement of implants into the S1pedicle and iliac bone. Use of trans-sacroiliac and S1 pedicle-iliacbone implants can also involve the risk of damage to the lumbosacralneurovascular elements. Damage to the lumbosacral neurovascular elementsas well as delayed union or non-union of the sacroiliac joint by use ofthese procedures may require revision surgery to remove all or a portionof the implants or repeat surgery as to these complications.

Another significant problem with conventional procedures utilizingminimally invasive small opening procedures can be that the proceduresare technically difficult requiring biplanar fluoroscopy of thearticular surfaces of the sacroiliac joint and extensive surgicaltraining and experience. Despite the level of surgical training andexperience, there is a substantial incidence of damage to thelumbosacral neurovascular elements. Additionally, sacral anomalies canfurther lead to mal-placement of implants leading to damage ofsurrounding structures. Additionally, these procedures are oftenperformed with out fusion of the sacroiliac joint which does not removethe degenerative joint surface and thereby does not address thedegenerative condition of the sacroiliac joint which may lead tocontinued or recurrent sacroiliac joint pain.

Another significant problem with conventional procedures can be theutilization of multiple trans-sacroiliac elongate implants, which do notinclude a threaded surface. This approach requires the creation oftrans-sacroiliac bores in the pelvis and nearby sacral foramen which canbe of relatively large dimension and which are subsequently broachedwith instruments which can result in bone being impacted into the pelvisand neuroforamen.

The creation of the trans-sacroiliac bores and subsequent broaching ofthe bores requires a guide pin which may be inadvertently advanced intothe pelvis or sacral foramen resulting in damage to other structures.Additionally, producing the trans-sacroiliac bores, broaching, orplacement of the elongate implants may result in damage to thelumbosacral neurovascular elements, as above discussed. Additionally,there may be no actual fusion of the articular portion of the sacroiliacjoint which may result in continued or recurrent pain requiringadditional surgery.

Another substantial problem with conventional procedures can be thatplacement of posterior extra-articular distracting fusion implants andbone grafts as described for example in U.S. patent application Ser. No.10/797,481 of Stark may be inadequate with respect to removal of thearticular surface or preparation of cortical bone, the implant structureand fixation of the sacroiliac joint. The method may not removesufficient amounts of the articular surfaces or cortical surfaces of thesacroiliac joint to relieve pain in the sacroiliac joint. The implantstructures described may have insufficient or avoid engagement with thearticular surfaces or cortical bone of the sacroiliac joint for adequatefixation or fusion. The failure to sufficiently stabilize and fuse thesacroiliac joint with the implant structures and methods described bythe Stark application may result in a failure to relieve the conditionof sacroiliac joint being treated. Additionally, the method of drivingapart a sacrum and ilium as described by Stark may lead to mal-alignmentof the sacroiliac joint and increased pain.

The inventive sacroiliac fusion system described herein addresses theproblems associated with conventional methods and apparatuses used infixation and fusion of the sacroiliac joint.

III. DISCLOSURE OF INVENTION

Accordingly, a broad object of the invention can be to provide aninventive sacroiliac joint implant for fixation and fusion of thesacroiliac joint. Embodiments of the sacroiliac joint implant canprovide an elongate body, which can further include at least one radialmember, or a pair of members which extend distance radially outward fromthe longitudinal axis of the elongate body adapted for non-transverseplacement between the articular surfaces of the sacroiliac joint and asto certain embodiments can further provide a third radial member andadditionally a fourth radial member each adapted to extend a distanceradially outward from the longitudinal axis of the elongate body intothe bone of the sacrum or the ilium.

Another broad object of the invention can be to provide an inventivemethod for fixation and fusion of the sacroiliac joint which utilizesthe inventive sacroiliac implant. The inventive method comprising thesteps of performing a minimally invasive posterior surgery that allowsaccess to the posterior aspect of the sacroiliac joint for removing asufficient portion of the articular cartilage or tissue between thearticular surfaces of the sacroiliac joint which can be replaced byembodiments of the above described sacroiliac implant. A portion of thesubcondral bone of the sacroiliac joint can be removed to provide animplant receiving space in the plane of the sacroiliac joint(non-trans-sacroiliac) configured to allow interference fitting of theelongate member, or the elongate member with at least a first radialmember between the opposed surfaces of the implant receiving space. Theinventive method can further include the step of providing the implantreceiving space with one or more radial member receiving channels cutinto the bone (including one or more of the subchondral, cortical, orcancellous) and thereby locating one or more radial members in the boneof the sacrum or the bone of the ilium. The inventive method avoidsconventional trans-sacroiliac placement of fixation elements or S1pedicle and intrailiac screws joined by a rod while providing immediatefixation of the sacroiliac joint.

Another broad object of the invention can be to provide one or more boneingrowth aperture elements which communicate between the opposedsurfaces of one or more radial members or through the generally linearelongate body each having a configuration which allows the bone of thesacrum and ilium to grow into or through the implant to facilitatefusion of the sacrum to the ilium and fixation of the sacroiliac joint.

Another broad object of the invention can be to provide particularembodiments of the inventive fixation fusion implant with an amount ofcurvature along the length of the implant which allows placement ofembodiments of the fixation fusion implant which have an increasedsurface area which remain within or substantially within the articularportion of the sacroiliac joint.

Naturally, further objects of the invention are disclosed throughoutother areas of the specification, drawings, photographs, and claims.

IV. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an anterior view of the pelvic region and a conventionalmethod and device for stabilizing the sacroiliac joint.

FIG. 2 is a perspective view of a particular embodiment of thesacroiliac joint implant.

FIG. 3 is a first side view of a particular embodiment of the sacroiliacjoint implant.

FIG. 4 is a first implant end view of a particular embodiment of thesacroiliac joint implant.

FIG. 5 is a second implant end view of a particular embodiment of thesacroiliac joint implant.

FIG. 6 is second side view of the particular embodiment of thesacroiliac joint implant shown in FIG. 3 rotated about 90 degrees aboutthe longitudinal axis.

FIG. 7 is a perspective view of a second particular embodiment of thesacroiliac joint implant.

FIG. 8 is a first side view of another particular embodiment of thefixation fusion implant having a coat material which facilitatesosseointegration of the fixation fusion implant with the bone.

FIG. 9 is a cross section 8-8 as shown in FIG. 8 of that particularembodiment of the fixation fusion implant.

FIG. 10 is a perspective view of an embodiment of the sacroiliac jointimplant having an amount of curvature along the longitudinal axis.

FIG. 11 is a first side view of the particular embodiment of thefixation fusion implant shown in FIG. 10.

FIG. 12 is a first implant end view of a particular embodiment of thefixation fusion implant shown in FIG. 11.

FIG. 13 is a second implant end view of a particular embodiment of thefixation fusion implant shown in FIG. 11.

FIG. 14 is second side view of the particular embodiment of the fixationfusion implant shown in FIG. 11 rotated about 90 degrees about thelongitudinal axis.

FIG. 15 is a side view of the embodiment of the sacroiliac joint implantshown in FIG. 10 produced in a plurality of implantable parts.

FIG. 16 is a cross section view through the sacroiliac joint whichillustrates a method of implanting an embodiment of the sacroiliac jointimplant the step including insertion of a needle into the articularplane of the sacroiliac joint to inject a radiographic dye to allowfluoroscopic visualization of the sacroiliac joint.

FIG. 17 is a cross section view through the sacroiliac joint whichillustrates a method of implanting an embodiment of the sacroiliac jointimplant the step including fixing the tubular needle within thesacroiliac joint as a guide wire.

FIG. 18 is a cross section view through the sacroiliac joint whichillustrates a method of implanting an embodiment of the sacroiliac jointimplant the step including advancing a body of a cannulated probe alongthe needle fixed in the sacroiliac joint to fixed location at theanterior portion of the sacroiliac joint.

FIG. 19 is a cross section view through the sacroiliac joint whichillustrates a method of implanting an embodiment of the sacroiliac jointimplant the step including advancing an tissue dialator along the bodyof the cannulated probe fixed in the sacroiliac joint to allow placementof a cannula against the surface of the sacrum and ilium to expose thesacroiliac joint.

FIG. 20A is a posterior view of the pelvic region showing fixedplacement of the cannula in relation to the sacroiliac joint havinginserted within a cannula alignment jig.

FIG. 20B is a perspective view of the cannula jig insert shown in FIG.20A having cross hairs.

FIG. 20C is a perspective view of the cannula shown in FIG. 20B having acannula alignment jig inserted within having alignable cross hairs.

FIG. 21A is a posterior view of the pelvic region showing fixedplacement of the cannula in relation to the sacroiliac joint havingwithin a first drill jig.

FIG. 21B is a perspective view of the cannula of FIG. 21A having withinthe first drill jig.

FIG. 22 is a cross section view through the sacroiliac joint whichillustrates a method of implanting an embodiment of the fixation fusionimplant the step including replacement of the tissue dialator with afirst drill jig which receives a cannulated drill for production of afirst bore hole substantially along the articular plane of thesacroiliac joint.

FIG. 23 is a cross section view through the sacroiliac joint whichillustrates a method of implanting an embodiment of the sacroiliacimplant the step including replacement of the first drill jig with asecond drill jig which allows additional bore holes to be produced inrelation to the first bore hole each substantially along the articularplane of the sacroiliac joint.

FIG. 24 is a cross section view through the sacroiliac joint whichillustrates a method of implanting an embodiment of the fixation fusionimplant the step including replacement of the second drill jig (or thefirst drill jig depending on the method) with a broach jig whichreceives a cannulated broach which can be advanced into the sacroiliacjoint to produce an implant receiving space.

FIG. 25 is a lateral view of the pelvic region which shows an embodimentof the sacroiliac joint implant located between the caudal articularsurfaces (shown in broken line) of the sacroiliac joint.

FIG. 26A provides a cutaway view of the sacroiliac joint showingplacement of a particular embodiment of the fixation fusion implant inthe implant receiving space produced by the method illustrated in FIGS.16-24.

FIG. 26B is an enlarged view of a portion of FIG. 26A showing placementof a particular embodiment of the fixation fusion implant in the implantreceiving space produced by the method illustrated in FIGS. 16-24.

FIG. 26C is a cross section view 26C-26C shown in FIG. 26B which showsthe configuration of the implant receiving space produced by the methodillustrated in FIGS. 16-25 and a particular embodiment of the fixationfusion implant implanted therein implanted.

FIG. 27 provides a lateral view of the pelvis showing an embodiment ofthe sacroiliac implant located between the cranial articular surfaces(shown in broken line) within articular plane of the sacroiliac joint.

FIG. 28A provides a cutaway view of the sacroiliac joint showingplacement of a particular embodiment of the fixation fusion implant inthe implant receiving space produced by the method illustrated in FIGS.16-24.

FIG. 28B is an enlarged view of a portion of FIG. 26A showing placementof a particular embodiment of the fixation fusion implant in the implantreceiving space produced by the method illustrated in FIGS. 16-24.

FIG. 28C is a cross section view 28C-28C shown in FIG. 28B which showsthe configuration of the implant receiving space produced by the methodillustrated in FIGS. 16-24 and a particular embodiment of the fixationfusion implant implanted therein implanted.

FIG. 29 provides a lateral view of the pelvis with an embodiment of thefixation fusion implant located substantially between the cranial andcaudal articular surfaces (shown in broken line) and to a limited extentextra-articular of the sacroiliac joint.

FIG. 30 provides a lateral view of the pelvis with an embodiment of thefixation fusion implant located between the cranial and caudal articularsurfaces (shown in broken line) within the articular plane of thesacroiliac joint.

FIG. 31 is a cross section view through the sacroiliac joint whichillustrates an alignment tool attachable to an implanted sacroiliacjoint implant which aligns an elongate member to pass through thesacroiliac joint implant.

FIG. 32 is a cross section view through the sacroiliac joint whichillustrates a coupling element joined to the first end of an implantedsacroiliac joint implant.

FIG. 33 is a posterior view of the pelvic region which shows a spanningmember joined to a corresponding pair of coupling elementscorrespondingly joined to the first end of a pair of implantedsacroiliac joint implants.

FIG. 34 is a posterior view of the pelvic region which shows a spanningmember joined to a corresponding pair of coupling elementscorrespondingly joined to an implanted sacroiliac joint implant anddirectly engaged to the sacrum.

V. MODE(S) FOR CARRYING OUT THE INVENTION

Generally, a sacroiliac joint fixation fusion system that provides amethod of fixation and fusion of the sacroiliac joint and a sacroiliacjoint implant which upon placement within the articular region of thesacroiliac joint facilitates stability and fusion of the sacroiliacjoint.

Now referring primarily to FIG. 1 which shows one commonly utilizedconventional method and device for fixation of the sacroiliac joint (1).The conventional device shown comprises one or more substantially linearelongate members (2) which can be inserted into correspondinglydimensioned trans-iliac bores (3) with a first portion extending intothe bone of sacrum (4) and a second portion extending into the bone ofthe ilium (5), thereby extending across the sacroiliac joint (1). Theone or more substantially linear elongate members (2) (which can beconfigured as cylindrical rods which can further include an amount oftaper or further include a spiral thread coupled to the exterior surfaceto avoid the need for generating trans-iliac bores) in trans-iliacplacement can locate the ilium (5) in fixed relation to the sacrum (4).However, this trans-iliac placement of such substantially linearelongate members (2) can have the disadvantages described above.Additionally, conventional placement of the trans-iliac bores (3) andthe elongate members (2) can be outside of that region defined by theboundary of the paired articular surfaces (16) (also commonly referredto as the “auricular surfaces”) of the sacroiliac joint (1), as furtherdescribed below.

Now referring primarily to FIGS. 2-6, an embodiment of an inventivesacroiliac joint implant (6) is shown which in part can include anelongate body (7) which having a longitudinal axis (8). The elongatebody (7) can have a configuration of sufficient dimension to avoiddeformation under the normal forces of surgical placement and fixationof the ilium (5) in relation to the sacrum (4). Accordingly, while theembodiment of the sacroiliac joint implant (6) shown in FIGS. 2-6 can begenerally cylindrical or circular in cross section; the invention is notso limited, and the elongate body (7) can have any of a numerous andvaried configurations in cross section consistent with the method hereinafter described such as oval, triangular, rectangular, square, diamond,or the like. As one non-limiting example, the generally cylindricalelongate body (7) shown in FIG. 2 can depending on the application havea diameter of in the range of about 0.5 centimeters (“cm”) to about 1 cmand a length disposed between a first implant end (11) and a second end(12) in the range of about 3 cm and about 6 cm.

As to particular embodiments of the invention, the elongate body (7) canfurther include an axial bore (9) that bounds an axial pathway (10)which communicates between a first implant end (11) and a second implantend (12) of the elongate body (7). The axial bore (9) allows forplacement within the axial pathway (10) a guide pin (13) (or other guidemember) about which embodiments of the sacroiliac joint implant (6) canbe guided for insertion and placement in the sacroiliac joint (1), asfurther described below.

Again referring primarily to FIGS. 2-6, embodiments of the sacroiliacjoint implant (6) can further include a first radial member (14) coupledto the external surface of the elongate body (7) extending radiallyoutward generally along the longitudinal axis (8). As to certainembodiments of the sacroiliac joint implant (6) as shown in the Figures,the first radial member (14) can extend along the longitudinal axis (8)substantially the entire length of the elongate body (7); however, theinvention is not so limited, and embodiments of the inventive sacroiliacjoint implant (6) can have a first radial member (14) which can in partor in a plurality of discontinuous parts extend along the longitudinalaxis (8) or the elongate body (7).

Again referring to FIGS. 2-6, embodiments of the sacroiliac jointimplant (6) can further include a second radial member (15). Each of thefirst radial member (14) and the second radial member (15) can extendradially outward from the elongate body (7) generally in opposedrelation (about 180 degrees apart about the longitudinal axis (8) of theelongate body (7); however, the invention is not so limited, and thefirst radial member (14) and the second radial member (15) can be spacedabout the elongate body (7) a greater or lesser number of degrees. Theconfiguration of each of the first radial member (14) or second radialmember (15) (or both) can be adapted to non-transversely locate betweenthe articular surfaces (16) of the sacroiliac joint (1) to dispose thesacrum (4) and the ilium (5) in substantially immobilized, immobilized,or fixed relation. The term “non-transversely” as used herein means notlying or extended across the joint between the sacrum (4) and the ilium(5) and in particular does not include trans-iliac placement of asacroiliac joint implant as above described and shown in FIG. 1. Theterm “articular surfaces” includes the two paired L-shaped surfacesformed between the surfaces of the sacrum (4) and the ilium (5) having acranial portion (87) and a caudal portion (86) as shown for example inFIGS. 25, 27, and 29 (broken line) and as used herein does not includestructures or regions of the sacrum (4) or the ilium (5) outside of thearticular surfaces (16), such as, the paired iliac tuberosity and sacralfossa.

Each of the first radial member (14) and the second radial member (15)can each provide a pair of opposed faces (17) (18) disposed a thickness(19A) apart and having an area bound by a top edge (20), a pair of sideedges (21) (22) and a bottom edge (23). The first of the pair of sideedges (21) can be connected as above described to the elongate body (7)locating the second side edge (22) a distance outward from thelongitudinal axis (8) of the elongate body (7). As a non-limitingexample, each of the first radial member (14) and the second radialmember (15) can be substantially rectangular in configuration having aheight (28 a) between the first of the pair of side edges (21) and thesecond of the pair of side edges (22) in the range of about 0.2 cm andabout 1 cm. Understandably, a lesser diameter elongate body (7) mayinclude a first radial member (14) and a second radial member (15) (orother radial members) having greater height (28 a) and a greaterdiameter elongate body (7) may require a first radial member (14) and asecond radial member (15) (or other radial members) having lesser height(28 a).

The top edge (20) of each of the first radial member (14) and the secondradial member (15) can terminate substantially in alignment with thefirst implant end (11) of the elongate body (7). The bottom edge (23) ofthe first radial member (14) and the second radial member (15) canterminate substantially in alignment with second implant end (12) of theelongate body (7). As to certain embodiments, the bottom edge (23) canfurther include an angle element (24) which angles outward from theelongate body (7) commencing at the second implant end (12) and joiningthe second of pair of side edges (22) a distance toward the firstimplant end (11). The angle element (24) can have a degree angle (25)from the perpendicular with the longitudinal axis (8) in a range ofabout fifteen degrees to about thirty degrees, as shown in FIG. 2;however, the invention is not so limited and the angle element (24) canbe a radius element, tapered element or other element to ease insertioninto the sacroiliac joint (1).

Again referring primarily to FIG. 2-6, certain embodiments of thesacroiliac joint implant (6) can further include a third radial member(26) extending along the longitudinal axis (8) of said elongate body (7)adapted to extend into the cortical bone of the ilium (5). Certainembodiments can further include a fourth radial member (27) extendingalong the longitudinal axis (8) of said elongate body (7) adapted toextend into the cortical bone of said sacrum (4). Certain embodiments ofthe third radial member (26) and the fourth radial member (27) can beadapted to extend into the bone of the sacrum (4) and the ilium (5)respectively.

As to the non-limiting embodiment of the sacroiliac joint implant (6)shown in FIG. 3, the third radial member (26) and the fourth radialmember (27) can be connected generally in line with the longitudinalaxis (8) of the elongate body (7). Each of the third radial member (26)and the fourth radial member (27) can extend radially outward from theelongate body (7) substantially in opposed relation (about 180 degreesapart) and in perpendicular relation (about 90 degrees) to the firstradial member (14) and the second radial member (15) (see also FIGS. 8and 9C); however, the invention is not so limited, and the third radialmember (26) and the fourth radial member (27) (if the embodimentincludes a fourth radial member (27)) can be spaced about the elongatebody (7) in relation to each other and in relation to the first radialmember (14) and the second radial member (15) a greater or lesser numberof degrees depending on the application and the amount of desiredengagement with the bone of the sacrum (4) or ilium (5).

The configuration of each of the third radial member (26) or the fourthradial member (27) can vary as necessary to provide an amount of surfacearea engagable with the bone of the sacrum (4) and ilium (5) sufficientfor facilitating substantial immobilization, immobilization, or to fix,the sacrum (4) in relation to the ilium (5) upon implantation of thesacroiliac joint implant (6) and to further provide a resistance torotation or other undesired movement of the sacroiliac joint implant (6)at the implant location within the region bounded by the articulatingsurfaces (16) of the sacroiliac joint (1). Accordingly, embodiments ofthe sacroiliac joint implant (6) having a third radial member (26) andthe fourth radial member (27) can provide a pair of opposed faces (17)(18) disposed a thickness (19 b) apart and have an area bound by a topedge (20), a pair of side edges (21) (22) and a bottom edge (23) insimilar configuration as above described for the first radial member(14) and the second radial member (15). The first of the pair of sideedges (21) can be connected as above described to the elongate body (7)locating the second side edge (22) a distance outward from thelongitudinal axis (8) of the elongate body (7). As a non-limitingexample, each of the third radial member (26) and the fourth radialmember (27) can have a substantially rectangular configuration having aheight (28 b) between the first of the pair of side edges (21) and thesecond of the pair of side edges (22) in the range of about 0.1 cm andabout 0.4 cm. The top edge (20) of each of the third radial member (26)and the fourth radial member (27) can terminate substantially inalignment with the first implant end (11) of the elongate body (7). Thebottom edge (23) of the third radial member (26) and the fourth radialmember (27) can terminate substantially in alignment with second implantend (12) of the elongate body (7). As to certain embodiments, the bottomedge (23) of the third radial member (26) and the fourth radial member(27) can further include the angle element (24) which angles the secondof the pair of side edges (22) toward the first implant end (11) of theelongate body (7). The angle element (24) can have a degree angle (25)from the perpendicular with the longitudinal axis (8) in a range ofabout fifteen degrees to about thirty degrees; however, the invention isnot so limited and with respect to certain embodiments of the inventionthere may be no angle element (24) or the angle element may be greateror less than within the range of about fifteen degrees to about thirtydegrees. Additionally, the angle element (24) can be similar as shown inthe figures or can be dissimilar between the radial members of aparticular sacroiliac joint implant (6) depending on the application.

Again referring primarily to FIGS. 2-6, and without limitation toforgoing, the third radial member (26) and the fourth radial member (27)can have a lesser height (28 b) than the first radial member (14) andsecond radial member (15). While the structure of the third radialmember (26) and the fourth radial member (27) appear similar to thefirst radial member (14) and the second radial member (15), the functioncan be substantially different. The first radial member (14) and thesecond radial member (15) have a configuration (height, length,thickness, surface area, and location in relation to the externalsurface of the elongate body (7), as above described) capable of orallowing placement non-transversely between the articular surfaces (16)(and not across) or within an implant receiving space (29) surgicallyproduced within the region bounded by the articular surfaces (16) byremoval of a portion the sacroiliac joint (1), as further describedbelow, capable upon placement between the articular surfaces (16) orwithin the implant receiving space (29) of substantially immobilizing orimmobilizing the sacroiliac joint (1).

By contrast, the third radial member (26), and as to those embodimentshaving a fourth radial member (27), can have a configuration (height,length, thickness, surface area, and location on the external surface ofthe elongate body (7), as above described) capable of being forciblyurged a depth into the cortical bone or the cancellous bone of thesacrum (4) or the ilium (5) or placed within the radial member receivingchannel (74) of the implant receiving space (29) upon non-transverselylocating the sacroiliac joint implant (6) between the articular surfaces(16) of the sacroiliac joint (1). The height of the third radial member(26) and the fourth radial member (27) can be sufficient to resistrotation of the implanted sacroiliac joint implant (6) to allow boneyfusion of the cancellous bone to the sacroiliac implant (6) or throughapertures of the third radial member (26) or the fourth radial member(27) or both similar to the first radial member (14) and second radialmember (15). Now referring primarily to FIG. 2, each radial member (14)(15) (26) (27) extending outwardly from the elongate body (7) canterminate in a radial member cross piece (98) disposed in substantiallyperpendicular relation to the surfaces of the radial member.

Again referring primarily to FIGS. 2-6, particular embodiments of thesacroiliac joint implant (6) can further include one or more apertureelements (31) which communicate between the opposed faces (17) (18) ofthe first radial member (14) or the second radial member (15) or both.The amount of open space of an aperture element (31) can be defined byan aperture perimeter (32) which can be of numerous and variedconfigurations of sufficient dimension to allow the surfaces of theilium (5) or sacrum (4) (or both) adjacent to the first radial member(14) or the second radial member (15) (or both) of the sacroiliac jointimplant (6) to grow a distance into the aperture element (31) or throughthe aperture element (31) or fuse within the aperture element (31) orfuse into material placed within the aperture element, the material caninclude: osseointegratable, osteoinductive, osteoconductive, osteogenicmaterials or biologically active agents, or combinations and permutationthereof. As a non-limiting example, the aperture perimeter (32) can beof generally oval configuration resulting in an oval aperture element(31) located in the first radial member (14) or the second radial member(15) (or both) (or located in additional radial members depending uponthe embodiment) with the length of the oval aperture element (31)aligned with the length of the first radial member (14) or second radialmember (15) and being about one quarter to about two thirds the lengthof the radial member and having a width of the oval aperture element(31) located between the sides (21) (22) of the first radial member (14)or second radial member (15) and being about one quarter to about twothirds the height (28 a). Additionally, the elongate body (7) canfurther include aperture elements (31) which communicate between theexternal surfaces between the radial members (14) (15) (26) (27).

Again referring primarily to FIGS. 2-7, embodiments of the sacroiliacjoint implant (6) can further include an anti-migration element (33)coupled to the first implant end (11) of the elongate body (7). Theanti-migration element (33) can take the form of an enlarged terminalportion of the first end of the elongate body (7) (as shown in FIGS.2-6), an increase in the height (28) of one or more of the radialmembers (such as flaring outward as shown in FIG. 7) proximate the firstimplant end (11) of the elongate body (7). As one non-limiting example,the anti-migration element (33) can take the form of an end cap (34)having a generally circular configuration with the center substantiallyaligned with the longitudinal axis (8) of the elongate member (7) andextending radially outward sufficient distance to prevent advancement ofthe second implant end (12) of the sacroiliac joint implant (6) furtherinto the sacroiliac joint (1) subsequent to implantation in the implantreceiving space (29). While the end cap (34) shown is generally circularin configuration, the end cap (34) can have end cap perimeter (35) whichdefines an oval, square, rectangle, or other configuration useful infixing the location of the sacroiliac joint implant (6) in relation thesacroiliac joint (1). Additionally, the anti-migration element (33) canhave sufficient dimensions to further include one or more bores (36)which communicate between the opposed surfaces (37) (38) of theanti-migration element (33) and dimensioned to receive mechanicalfasteners (39) (such threaded members, barbed members, locking membersor the like) which can be driven or rotated to engage a portion of themechanical fastener with the sacrum (4) or the ilium (5). Now referringprimarily to FIG. 2, the anti-migration element (33) can also take theform of tapered elements on a part or the entirety of the externalsurface which taper outward from the surface allowing insertion ofembodiments of the sacroiliac joint implant (6) but opposes backwardtravel. Now referring primarily to FIG. 7, the anti-migration element(33) can take the form of tapered terminal end (33/99) of the sacroiliacjoint implant (6) which resists forward or backward travel of thesacroiliac joint implant (6).

The elongate body (7) along with the other elements of the sacroiliacjoint implant (6) above described can be fabricated or formed from aplurality of pieces or as a single piece of biocompatible material or acombination of biocompatible and biodegradable materials of suitablydimensioned particles, sheets, or other constructional forms or formableor moldable materials suitably bound or formed or molded to provideconfigurations in accordance with the invention.

Now referring primarily to FIGS. 8 and 9, embodiments of the sacroiliacjoint implant (6) can further include a coat (40) coupled, generated orintegral to all or a part of the external surface of the sacroiliacjoint implant (6). The coat (40) can be of any composition that can becoupled to the sacroiliac joint implant (6) capable of biocompatibleosseointegration with the bone of the ilium (5) and sacrum (4), such aspure alumina, titanium-dioxide, hydroxyapatite, calcium triphosphate, orthe like. As a non-limiting example, the coat (40) can be applied byplasma spraying with a plasma torch, plasmatron or a plasma gun.Alternately, the coat (40) can be achieved by producing a surfaceroughness, porosity, or irregularity of the sacroiliac joint implant (6)by sand blasting, bead blasting, molding, or the like. The coat (40) canhave a thickness in the range of about 40 μm and about 100 μm. Again,embodiments of the sacroiliac joint implant (6) can be configured as amaterial having interconnecting pores throughout such as TRABECULARMETAL available from Zimmer, P.O. Box 708, 1800 West Center Street,Warsaw, Ind. 46581-0708 or a metallic foam such as a titanium foamavailable from the National Research Council Canada, 1200 Montreal Road,Bldg. M-58, Ottawa, Ontario, Canada or fully-engineered, porous,titanium structures such as TRABECULITE available from Tecomet, 115Eames Street, Wilmington, Mass. 01887.

Again referring primarily to FIG. 2 and FIGS. 3-6, embodiments of theinvention can further include one or more biologically active agent(s)(41) which can be applied directly to the external surface of thesacroiliac joint implant (6) or can be mixed with a biocompatiblematerial or biocompatible biodegradable material or biocompatibleosseointegratable material (collectively numeric indicator (100) whichcan be applied to the external surface of the sacroiliac joint implant(6) or otherwise made a part of the sacroiliac joint implant (6). As toparticular embodiments of the fixation fusion implant (6), thebiologically active agent(s) (41) can be mixed with an amount of abiocompatible biodegradable material or osseointegrateable material(100) and located within one or more of the aperture elements (31).

“Biocompatible” for the purposes of this invention means the ability ofany material to perform the intended function of an embodiment of theinvention without eliciting any undesirable local or systemic effects onthe recipient and can include non-biodegradable materials such as:ceramic; metals or steels such as titanium alloys or rigid polymericmaterials or rigid laminate materials or composites which includesuitably dimensioned particles of metals or steels dispersed withinrigid laminate materials, or suitably sized particles of biocompatiblematerials suitably bound or formed to provide configurations,polyurethanes, polyisobutylene, ethylene-alpha-olefin copolymers,acrylic polymers and copolymers, vinyl halide polymers and copolymers,polyvinyl esters, polyvinylidene chloride, polyacrylonitrile, polyvinylketones, polyvinyl aromatics such as polystyrene, copolymers of vinylmonomers and olefins such as ethylene-methyl methacrylate copolymers,acrylonitrile-styrene copolymers, ABS resins, ethylene-vinyl acetatecopolymers, polyamides such as Nylon 66 and polycaprolactone, alkydresins, polycarbonates, polyoxyethylenes, polyimides, polyesters, epoxyresins, rayon-triacetate, cellophane, polyether ether ketone (PEEK),polyetherketoneketone (PEKK), bone-from-wood available from the Istitutodi Scienza e Tecnologia dei Mareriali Ceramici, Faenza, Italy, or thelike, or biodegradable materials, as herein described.

“Biodegradable” for the purposes of this invention means the ability ofany biocompatible material to breakdown within the physiologicalenvironment of the sacroiliac joint by one or more physical, chemical,or cellular processes at a rate consistent with providing treatment of acondition of the sacroiliac joint at a therapeutic level controllable byselection of a polymer or mixture of polymers (also referred to aspolymeric materials), including, but not limited to: polylactidepolymers (PLA), copolymers of lactic and glycolic acids (PLGA),polylactic acid-polyethylene oxide copolymers,poly(ε-caprolactone-co-L-lactic acid (PCL-LA), glycine/PLA copolymers,PLA copolymers involving polyethylene oxides (PEO), acetylated polyvinylalcohol (PVA)/polycaprolactone copolymers,hydroxybutyrate-hydroxyvalerate copolymers, polyesters such as, but notlimited to, aspartic acid and different aliphatic diols, poly(alkylenetartrates) and their copolymers with polyurethanes, polyglutamates withvarious ester contents and with chemically or enzymatically degradablebonds, other biodegradable nonpeptidic polyamides, amino acid polymers,polyanhydride drug carriers such as, but not limited to, poly(sebacicacid) (PSA), aliphatic-aromatic homopolymers, andpoly(anhydride-co-imides), poly(phosphoesters) by matrix or pendantdelivery systems, poly(phosphazenes), poly(iminocarbonate), crosslinkedpoly(ortho ester), hydroxylated polyester-urethanes, or the like.

“Biologically active agents” for the purposes of this invention meansthose agents or mixture of agents which can be varied in kind or amountto provide a therapeutic level effective to mediate the formation orhealing of bone, cartilage, tendon, or to reduce, inhibit, or prevent asymptom of a condition of the sacroiliac joint subsequent to placementof an embodiment of the fixation fusion implant within the sacroiliacjoint (1) such as infection or pain and without limitation can includeagents that influence the growth of bone, demineralized bone matrix,stem cells, alleografts, autografts, xenografts, bone forming proteinwhether naturally occurring, synthetic, or recombinate, growth factors,cytokines, bone morphogenetic protein 2, bone morphogenetic protein 7,analgesics, anesthetics, anti-inflammatory agents, antibacterials,antivirals, antifungals, antiprotozoals, anti-infectives, antibioticssuch as aminoglycosides such as gentamicin, kanamycin, neomycin, andvancomycin; amphenicols such as chloramphenicol; cephalosporins, such ascefazolin HCl; penicillins such as ampicillin, penicillin,carbenicillin, oxycillin, methicillin; lincosamides such as lincomycin;polypeptide antibiotics such as polymixin and bacitracin; tetracyclinessuch as tetracycline, minocycline, and doxycycline; quinolones such asciprofloxacin, moxifloxacin, gatifloxacin, and levofloxacin; anti-viraldrugs such as acyclovir, gancyclovir, vidarabine, azidothymidine,dideoxyinosine, dideoxycytosine; analgesics, such as codeine, morphine,ketorolac, naproxen, an anesthetic, lidocaine; cannabinoids; antifungalagents such as amphotericin; anti-angiogenesis compounds such asanecortave acetate; retinoids such as tazarotene, steroidalanti-inflammatory agents such as 21-acetoxypregnenolone, alclometasone,algestone, amcinonide, beclomethasone, betamethasone, budesonide,chloroprednisone, clobetasol, clobetasone, clocortolone, cloprednol,corticosterone, cortisone, cortivazol, deflazacort, desonide,desoximetasone, dexamethasone, diflorasone, diflucortolone,difluprednate, enoxolone, fluazacort, flucloronide, flumethasone,flunisolide, fluocinolone acetonide, fluocinonide, fluocortin butyl,fluocortolone, fluorometholone, fluperolone acetate, fluprednideneacetate, fluprednisolone, flurandrenolide, fluticasone propionate,formocortal, halcinonide, halobetasol propionate, halometasone,halopredone acetate, hydrocortamate, hydrocortisone, loteprednoletabonate, mazipredone, medrysone, meprednisone, methylprednisolone,mometasone furoate, paramethasone, prednicarbate, prednisolone,prednisolone 25-diethylamino-acetate, prednisolone sodium phosphate,prednisone, prednival, prednylidene, rimexolone, tixocortol,triamcinolone, triamcinolone acetonide, triamcinolone benetonide,triamcinolone hexacetonide; or allograft cellular matrix containingviable mesenchymal stem cells such as OSTEOCEL PLUS available fromNuVasive, Inc., 7475 Lusk Blvd., San Diego, Calif. 92121 USA, and any oftheir derivatives, whether separately or in combinations thereof.

As to particular embodiments of the inventive fixation fusion implant(6) the biologically active agent(s) (41) can be dispersed throughout abiocompatible or biocompatible biodegradable material (or mixture ofbiocompatible materials or mixture of biocompatible biodegradablematerials) by mixing biologically active agent(s) (41) into the meltedbiocompatible or biodegradable polymer and then solidifying theresulting material by cooling, having the biologically active agent(s)(41) substantially uniformly dispersed throughout. The biodegradablematerial or biocompatible material or mixture thereof can be selected tohave a melting point that is below the temperature at which thebiologically active agent(s) (41) becomes reactive or degrades.Alternatively, the biologically active agent(s) (41) can be dispersedthroughout the biocompatible or biodegradable material by solventcasting, in which the biocompatible or biodegradable material isdissolved in a solvent, and the biologically active agent(s) (41)dissolved or dispersed in the solution. The solvent is then evaporated,leaving the biologically active agent(s) (41) in the matrix of thebiocompatible or biodegradable material. Solvent casting requires thatthe biocompatible or biodegradable material be soluble in organicsolvents. Alternatively, the fixation fusion implant (6) can be placedin a solvent having a concentration of the biologically active agent(s)(41) dissolved and in which the fixation fusion implant (6) or thebiocompatible or biocompatible biodegradable material located in theaperture elements, or applied to the external surface, swells. Swellingof the fixation fusion implant (6) or portions thereof draws in anamount of the biologically active agent(s) (41). The solvent can then beevaporated leaving the biologically active agent(s) (41) within thebiocompatible or biocompatible biodegradable material. As to each methodof dispersing the biologically active agent(s) (41) through out thebiocompatible or biodegradable biocompatible material of or coupled tothe fixation fusion implant (6), therapeutic levels of biologicallyactive agent(s) (41) can be included in biocompatible biodegradablematerial to provide therapeutically effective levels of the biologicallyactive agent to the sacroiliac joint (I) to treat a particularsacroiliac joint condition.

Other non-active agents (42) may be included in the biocompatiblebiodegradable material for a variety of purposes. For example, bufferingagents and preservatives may be employed. Preservatives which may beused include, but are not limited to, sodium bisulfite, sodiumbisulfate, sodium thiosulfate, benzalkonium chloride, chlorobutanol,thimerosal, phenylmercuric acetate, phenylmercuric nitrate,methylparaben, polyvinyl alcohol and phenylethyl alcohol. Examples ofbuffering agents that may be employed include, but are not limited to,sodium carbonate, sodium borate, sodium phosphate, sodium acetate,sodium bicarbonate, and the like, as approved by the FDA or otherappropriate agencies in the United States or foreign countries, for thedesired route of administration. Electrolytes such as sodium chlorideand potassium chloride may also be included in the formulation.

A non-limiting example, embodiments of the fixation fusion implant (6)having a biocompatible biodegradable portion with biologically activeagent(s) (41) for treating the sacroiliac joint (1) can be made bydispersing a biologically active agent(s) (41) in a biocompatiblebiodegradable material as above described to provide biologically activeagent(s) (41) release characteristics at a therapeutic level. Uponimplantation of the fixation fusion implant (6) in the sacroiliac joint(1) as described below, the biocompatible biodegradable portion of thefixation fusion implant (6) can substantially continuously releasebiologically active agent (41) to provide a localized amount of bonemorphogenetic protein 2 at therapeutic levels of about 1 milligram toabout 4 milligrams to facilitate bone regrowth. It is to be understoodthat this specific example of providing an embodiment of the fixationfusion implant (6) which delivers an amount of bone morphogeneticprotein 2 to facilitate bone regrowth, is not intended to be limiting,and embodiments of the fixation fusion implant (6) can be utilized todeliver numerous and varied active agent(s) (41) individually or incombination to treat a wide range of conditions of the sacroiliac joint(1) subsequent to implantation of embodiments of the fixation fusionimplant (6).

Now referring primarily to FIGS. 10-15 and 30, particular embodiments ofthe invention can further include an amount of curvature (43) betweenthe first implant end (11) and the second implant end (12) of thefixation fusion implant (6). The amount of curvature (43) can vary fromembodiment to embodiment of the fixation fusion implant (6) depending onthe application between a substantially linear elongate body (7) asabove described to including an amount of curvature (43) which defines aradius to facilitate placement in the cranial portion (87) and a caudalportion (86) between the articular surfaces (16) of the sacroiliac joint(1) or in the corresponding implant receiving space (29). As onenon-limiting embodiment the radius can be within a range of about 2 cmand about 6 cm.

Now referring primarily to FIG. 15, certain embodiments of the inventionhaving an amount of curvature can be provided in a plurality of implantsegments (101) (102) (103) which can be individually implanted withinthe articular region (44) as shown in FIG. 25, 27, or 29 by the methodbelow described.

Additionally, embodiments of the sacroiliac joint implant (6) can beconfigured to house a bone growth stimulator (105). Useful implantablegrowth stimulators can directly engage the anode of a battery and asingle or double titanium cathode wire implanted within or in closeproximity to the sacroiliac joint implant (6). The cathode wire can bedisposed a distance into the host bone, bone graft, or portions of thedevice, preferably with the cathode ends contacting and or anchored intoliving bone. Embodiments of the invention can include a metal implantwith an insulation material, such as PEEK, to prevent cathode-metalcontact, while permitting cathode-bone contact. The battery can beplaced in an extrafascial, subcutaneous pocket for removable placement.A suitable growth stimulator is available from Biomet Trauma 100Interpace Pkwy #1, Parsippany, N.J. 07054-1149.

Understandably, a plurality of inventive sacroiliac joint implants (6)whether separately or in joined relation, whether the same or differentembodiments, can be utilized with conventional or the inventive methodsof implantation herein described for fixation and fusion of thesacroiliac joint (1). As one example, a plurality of elongate bodies (7)can be joined in fixed, substantially fixed or movable relation toprovide an embodiment of the sacroiliac joint implant (6).

Now referring primarily to FIGS. 16-24, a non-limiting method ofaccessing an articular region (44) between the articulating surfaces(16) of the sacroiliac joint (1) and placing a sacroiliac joint implant(6) non-transversely between the articulating surfaces (16) within thearticular region (44) of the sacroiliac joint (1) to dispose the sacrum(4) and the ilium (5) in substantially immobilized relation bycorresponding engagement of the sacroiliac joint implant (6) by thearticulating surfaces (16) of the sacroiliac joint (1). The particularexample of the method described is sufficient to enable a person ofordinary skill in the art to utilize embodiments of the sacroiliac jointimplant (6) and is not intended to be limiting with respect to the orderof steps or the use of all or any of the steps or combination of one ormore steps into one steps or performing any one step as substeps, orother similar, equivalent, or conventional steps to implant embodimentsof the sacroiliac joint implant within the sacroiliac joint. (1).

Now referring primarily to FIG. 16, an embodiment of the method caninclude the step of placing a patient under sedation prone on atranslucent operating table (or other suitable surface). The sacroiliacjoint (1) can be locally anesthetized to allow for injecting aradiographic contrast (46) (as a non-limiting example, Isoview 300radiographic contrast) under fluoroscopic guidance into the inferioraspect of the sacroiliac joint (1) to outline the articular surfaces(16) of the sacroiliac joint (1). Injection of the radiographic contrast(46) within the sacroiliac joint (1) can be accomplished utilizing atubular member (47) (such as a syringe needle) having first tubularmember end (48) which can be advanced between the articulating surfaces(16) of the sacroiliac joint (1) and having a second tubular member end(49) which removably couples to a hub (50). The hub (50) can beconfigured to removably couple to a syringe barrel (51) (or other deviceto contain and deliver an amount of radiographic contrast (46)). In theexample of a syringe barrel (51), the syringe barrel (51) can have aninternal volume capable of receiving an amount of the radiographiccontrast (46) sufficient for outlining the lateral articular surfaces(16) of the sacroiliac joint (1). A plunger (52) can be slidinglyreceived within the barrel (51) to deliver the radiographic contrast(46) through the tubular member (47) into the sacroiliac joint (1). Thetubular member (47) can have a gauge in the range of about 16 gauge andabout 20 gauge and can further be incrementally marked on the externalsurface to allow determination of the depth at which the first needleend (48) has advanced within the sacroiliac joint (1). As the firstneedle end (48) advances into the sacroiliac joint (1) the radiographicdye (46) can be delivered from within the syringe barrel (51) into thesacroiliac joint (1) to allow visualization of the sacroiliac joint (1)and location of the tubular needle (47) within the sacroiliac joint (1).

Now referring primarily to FIG. 17, once the first tubular member end(48) has been sufficiently advanced into the sacroiliac joint (1) andthe articular surfaces (16) of the sacroiliac joint (1) have beensufficiently visualized, the hub (50) can be removed from the tubularmember (47) leaving the tubular member (47) fixed within the sacroiliacjoint (1) as a initial guide for tools subsequently used to locate orplace the sacroiliac joint implant (6) non-transversely between thearticulating surfaces (16) of the sacroiliac joint (1) or in removal ofa portion of the sacroiliac joint (1) within the region defined by thearticular surfaces (16) to generate an implant receiving space (29).Alternately, one or more guide pins (13) can be inserted alongsubstantially the same path of the tubular member (47) for fixedengagement within the sacroiliac joint (1) and used in subsequent stepsas a guide(s).

Now referring primarily to FIGS. 18, a small incision can be made in theskin at the posterior superior (or as to certain embodiments inferior)aspect of the sacroiliac joint (1), extending proximal and distal to thetubular member (47) along the line of the sacroiliac joint (1) toprovide a passage to access the interarticular space between thearticulating surfaces (16) of the sacroiliac joint (1). A cannulatedprobe (53) can be slidingly engaged with the tubular member (47) (orguide pin (13)) extending outwardly from the sacroiliac joint (1) (whilethe sacroiliac joint may be shown in the figures as being substantiallylinear for illustrative purposes, it is to be understood that the normalirregular features of the sacroiliac joint have not been removed). Thecannulated probe (53) can have a probe body (54) of generallycylindrical shape terminating in a spatulate tip (55) at the endadvanced into the sacroiliac joint (1). A removable cannulated probehandle (56) couples to the opposed end of the probe body (54). Thespatulate tip (55) can be guided along the tubular needle (47) (or guidewire (13) into the posterior portion of the sacroiliac joint (1) andadvanced to the anterior portion of the sacroiliac joint (1) underlateral fluoroscopic visualization. The cannulated probe handle (56) canthen be removed providing the generally cylindrical probe body (54)extending outwardly from the sacroiliac joint (1) through the incisionmade in the skin.

Now referring primarily to FIG. 19, a passage from the incision to thesacroiliac joint (1) can be generated by inserting a cannula (57) intothe incision. A soft tissue dilator (58) having a blunt end (59) can beadvanced over the probe body (54), or a plurality of soft tissuedilators of increasing size, until the blunt end (59) of the soft tissuedilator (58) and the corresponding cannula end (45) contact theposterior aspect of the sacroiliac joint (1). The soft tissue dilator(58) can be removed from within the cannula (57). The external surfaceof the cannula (57) can be sufficiently engaged with the surroundingtissue to avoid having the tissue locate with in the hollow inside ofthe cannula (57). A non-limiting embodiment of the cannula (57) providesa tubular body having substantially parallel opposed side walls whichterminate in a radius at both ends (lozenge shape) into which aplurality of different jigs can be inserted.

Now referring primarily to FIG. 20A-20C, a cannula alignment jig (60)can be advanced over the probe body (54) (or guide pins (13)) andreceived within the cannula (57). Substantially, identical cross hairs(63) (64) can be disposed on the upper jig surface (65) and the lowerjig surface (66). Alignment of the cross hairs (63) (64) under x-raywith the sacroiliac joint (1) can confirm that the cannula (57) hasproper orientation in relation to the paired articular surfaces (16) ofthe sacroiliac joint (1). The cannula (57) properly oriented with thepaired articular surfaces (16) can than be disposed in fixed relation tothe sacroiliac joint by placement of fasteners through the cannula (57)into the sacrum (4) or the ilium (5).

Now referring to FIGS. 21A and 21B, a first drill jig (67) can beadvanced over the probe body (54) (or guide pins (13) and receivedwithin the cannula (57). The probe body (54) (or guide pins (13))extending outwardly from the sacroiliac joint (1) passes through a drillguide hole (68) of the first drill jig (67) (or a plurality of guidepins (13) can extend through a corresponding plurality of guide pinholes (69)). The drill guide hole (68) can take the form of a circularhole as shown in the Figures, a slot, or other configuration to restrictthe movement of the drill bit (62) within the drill jig (60) and providea guide for a drill bit (62) in relation to the sacroiliac joint (1).

Now referring to FIG. 22, a cannulated drill bit (70) can be advancedover the probe body (54) and within a drill guide hole (68) of the firstdrill jig (67). The cannulated drill bit (70) under fluoroscopicguidance can be advanced into the interarticular region (44) between thearticulating surfaces (16) of the sacroiliac joint (1) to produce afirst bore (71) (shown in broken line) to a determined depth. As tocertain embodiments of the method, an amount of articular cartilage orother tissues from between the articular surfaces (16) of the sacroiliacjoint (1) can be removed sufficient to allow embodiments of thesacroiliac joint implant (6) to be implanted in replacement of theremoved articular cartilage or tissue. Because the method removes thedegenerative articular cartilage or tissue between the articularsurfaces (16) of the sacroiliac joint (1), the articular surfaces (16)of the sacroiliac joint (1) can remain intact or substantially intactallowing the sacroiliac joint implant (6) to be non-transverely locatedbetween the articular surfaces (16) of the sacroiliac joint (1).Understandably, other instruments can be utilized separately or incombination with a cannulated drill bit (62) for the removal ofarticular cartilage or tissue between articular surfaces (16) such as:box chisels, burs, hole saws, curettes, lasers (such as CO2,Neodymium/YAG (yttrium-aluminum-garnet), argon, and ruby),electrosurgical equipment employing electromagnetic energy (the cuttingelectrode can be a fine micro-needle, a lancet, a knife, a wire or bandloop, a snare, an energized scalpel, or the like) where the energytransmitted can be either monopolar or bipolar and operate with highfrequency currents, for example, in the range of about 300 kHz and about1000 kHz whether as pure sinusoidal current waveform where the “crestfactor” can be constant at about 1.4 for every sinus waveform, and avoltage peak of approximately 300 V to enable a “pure” cutting effectwith the smallest possible coagulation effect or as amplitude modulatedcurrent waveforms where the crest factor varies between 1.5 and 8, withdecreasing crest factors providing less of a coagulation effect.Electrosurgical waveforms may be set to promote two types of tissueeffects, namely coagulation (temperature rises within cells, which thendehydrate and shrink) or cut (heating of cellular water occurs sorapidly that cells burst). The proportion of cells coagulated to thosecut can be varied, resulting in a “blended” or “mixed” effect.Additionally, a fully rectified current, or a partially rectifiedcurrent, or a fulguration current where a greater amount or lateral heatis produced can be employed to find the articular surfaces of the jointand aid in advancing a probe or guide wire into a position in betweenthe articulating surfaces. These currents can effectively degrade thecartilage and allow advance into the joint without grossly penetratingmuch beyond the cartilage.

Now referring to FIG. 23, as to certain embodiments of the invention,the first drill jig (67) can be removed from within the cannula (57) anda second drill jig (72) can be advanced over the probe body (54) andreceived within the cannula (57); however, the invention is not limitedto any particular number of drill jigs and as to certain embodiments ofthe method the first drill jig (67) can include all the required drillguide hole(s) (68) (or slots or other configurations of the drill guide)and as to other embodiments of the method a plurality of drill jigs canbe utilized in serial order to provide all the drill guide holes (68).As to the particular embodiment of the invention shown by the Figures,the first drill jig (67) can provide one or more additional drill guideholes (68) which guide in relation to the first bore (71) a second ormore cannulated drills (62) of the same or different configuration to beinserted within and advanced into the sacroiliac joint (1) to produce asecond bore (73) (generally shown in broken line as 71/73) or aplurality of bores within the sacroiliac joint (1) spaced apart inpredetermined pattern to allow removal of sufficient articular cartilage(16) or other tissue from the interarticular space of sacroiliac joint(1) for placement of embodiments of the sacroiliac joint implant (6)within the region defined by and between the paired articular surfaces(16) of the sacroiliac joint (1). As to certain methods of theinvention, the first drill jig (67) or the second drill jig (72) or aplurality of drill jigs can be utilized in serial order to remove aportion of the sacroiliac joint (1) for generation of an implantreceiving space (29). As these embodiments of the method, articularcartilage or other tissues and sufficient subchondral bone can beremoved from between the articular surfaces (16) of the sacroiliac joint(1) sufficient to allow placement of certain embodiments of thesacroiliac joint implant (6) and one or more radial member receivingchannels (74) can be cut into at least one of the articular surfaces(16) of said sacroiliac joint (1) sufficient to receive otherembodiments of the sacroiliac implant (6). The one or more radial memberreceiving channels (74) can be cut a depth into the subchondral,cortical bone or cancellous bone of the sacrum (4) or ilium (5).

Now referring primarily to FIG. 24, in a subsequent step, the last inthe serial presentation of drill jigs (67) (72) can be removed fromwithin the cannula (57) and a broach jig (75) can be advanced over theprobe body (54) to locate within the cannula (57). The broach jig (75)can include a broach guide hole (76) which receives a first broach end(77) of a cannulated broach (78) advanced over the probe body (54). Thefirst broach end (77) can have a configuration which can be advancedinto the sacroiliac joint (1). As to certain embodiments of the method,the first broach end (77) can be adapted to remove an amount ofarticular cartilage and other tissue from the between the articularsurfaces (16) within the articular region (44) of the sacroiliac joint(1) for non-transverse placement of a sacroiliac joint implant (6)having an elongate body (7), or having an elongate body (7) and a firstradial member (14), or an elongate body (7) having a first and secondradial members (14) (15) between the articular surfaces (16) of thesacroiliac joint (1). As to other embodiments of the method, thecannulated broach (78) can remove a sufficient a portion of thesacroiliac joint (1) to generate an implant receiving space (29) toreceive embodiments of the sacroiliac joint implant (6) having anelongate body (7), an elongate body (7) and at least one radial member(14) adapted for non-transverse placement between the articular surfaces(16) or at least one radial member (26) adapted to extend into the boneof the sacrum (4) or the ilium (5). As a non-limiting example, FIG. 24shows a broach (78) configured to remove a portion of the sacroiliacjoint (1) to produce a implant receiving space (29) to receiveembodiments of the sacroiliac joint implant (6) having and elongate body(7) to which a first radial member (14) and a second radial member (15)extend along the longitudinal axis (8) of the elongate body (7) insubstantially opposed relation adapted to locate between the articularsurfaces (16) of the sacroiliac joint (1) and further having a thirdradial member (26) and a fourth radial member (27) which extend alongthe longitudinal axis (8) of the elongate member (7) in substantiallyopposed relation adapted to correspondingly extend correspondingly intothe bone of the sacrum (4) and the ilium (5).

Now referring primarily to FIGS. 25 and 26A, 26B, and 26C, the implantreceiving space (29) and the sacroiliac joint implant (6) can beconfigured having related dimension relations such that placement of thesacroiliac joint implant (6) within the implant receiving space (29)disposes the sacrum (4) and the ilium (5) in substantially immobilizedrelation and substantially avoids alteration of the positional relationof the sacrum (4) and the ilium (5) from the normal condition, or avoidsdriving together or driving apart the sacrum (4) from the ilium (5)outside of or substantially outside of the normal positional relation.An intention in selecting configurations of the sacroiliac joint implant(6) and the implant receiving space (29) being immobilization of thesacrum (4) in relation to the ilium (5) while maintaining the sacroiliacjoint (1) in substantially normal or substantially normal positionalrelation, or returning the sacroiliac joint (1) to a substantiallynormal positional relation to correct a degenerative condition of thesacroiliac joint (1).

As a non-limiting example, configurations of an implant receiving space(29) allow embodiments of the sacroiliac joint implant (6) to be placednon-transversely between the caudal portion (86) of the articularsurfaces (16) of the sacroiliac joint (1). While certain embodiments ofthe sacroiliac joint implant (6) may only provide an elongate body (7)which locates within a correspondingly configured implant receivingspace (29) to engage at least a portion of the bone of the ilium (5);the invention is not so limited, and can further include at least afirst radial member or a first and a second radial member at least aportion of the external surface of the first radial member (14) engaginga portion of the bone (73) of the sacrum (4) and the ilium (5). As tothose embodiments of the sacroiliac joint implant (6) which have a thirdradial member (26) and a fourth radial member (27) the implant receivingspace (29) an further include one more radial member receiving channels(74)) which correspondingly allow the third and fourth radial members(26) (27) to extend into the bone of the sacrum (4) or the ilium (5)(whether subchondral, cortical, cancellous, or the like), or impact ofthe sacroiliac joint implant (6) into the implant receiving space (29)without the radial member receiving channels (74) can forcibly urge theradial members (26) (27) into the bone of the sacrum (4) and the ilium(5). Mechanical fasteners (39) (such as treaded members) can be insertedthrough the bores (36) in the anti-migration element (33) and into thesacrum (4) and ilium (5) to fix location of the fixation fusion implant(6) within the implant receiving space (29).

Now referring to FIGS. 27 and 28A, 28B and 28C, as second a non-limitingexample, configurations of an implant receiving space (29) allowembodiments of the sacroiliac joint implant (6) to be placednon-transversely between the cranial portion (86) of the articularsurfaces (16) of the sacroiliac joint (1) by the similar procedures orsteps as above described with the incision and generation of the passageto the superior articular portion of the sacroiliac joint (1).

Now referring to FIGS. 29 and 30, configurations of an implant receivingspace (29) allow embodiments of the sacroiliac joint implant (6) to beplaced non-transversely between the cranial portion (87) and caudalportion (86) of the articular surfaces (16) of the sacroiliac joint (1)by the similar procedures or steps as above described with the incisionand generation of the passage to the inferior articular portion of thejoint.

Now referring primarily to FIG. 31, which shows an embodiment of thesacroiliac joint implant (6) having a portion of the axial bore (9)adapted to fixedly mate with a portion of an alignment tool (79). Thealignment tool (79) can have a fixed or adjustably fixed configurationwhich aligns a cannulated alignment guide (80) with one of the bores(36) through the sacroiliac joint implant (6). An insertion tool (81)can be slidingly engaged with the cannulated alignment guide (80). Anelongate member (85) can be removably fixedly attached to the firstinsertion tool end (82) proximate the bore (36) in the sacroiliac jointimplant (6). The second insertion tool end (83) can be forcibly advancedin the cannulated alignment guide (80) to advance the elongate member(81) to pass through the bore (36) to dispose the elongate member (81)in transverse relation to said articular surfaces (16) correspondinglyengaged with sacroiliac joint implant (6). As a non-limiting example,the elongate member (81) can have a spiral thread (84) coupled to theexternal surface and by rotation of the second end (83) of the insertiontool (81) the elongate member (85) can be drawn through the bore (36) ofthe sacroiliac joint implant (1) in transverse relation to saidarticular surfaces (16) correspondingly engaged with sacroiliac jointimplant (6). By further operation of the elongate member (85) thearticular surfaces (16) of the sacroiliac joint (1) can be drawn againstthe external surfaces of the sacroiliac joint implant (6).

Now referring primarily to FIG. 32, embodiments of the invention canfurther comprise a coupling element (87) connected to the first end (11)of the sacroiliac joint implant (6). As a non-limiting example, thecoupling element (87) can be disposed in fixed relation to the first end(11) of the sacroiliac joint implant (6) by threaded engagement of afastener portion (88); however, the invention is not so limited and thefastener portion (88) can be connected to the first end (11) of thesacroiliac joint implant (6) by any method such as welding, spinwelding, adhesive, or the like. The coupling element (87) can furtherprovide a coupling portion (89) configured to join with a numerous andwide variety of cross sectional geometries of spanning members (90). Asa non-limiting example, the coupling portion (89) can be configured ascylindrical cup (91) pivotally coupled to the fastener portion (88). Aspiral thread can be coupled to the internal surface of the cylindricalcup (91) to rotationally receive a spirally threaded body (92). The sidewall (93) of the cylindrical cup (91) can include a pass through element(94) in which part of a spanning member (90) can be received. The partof the spanning member (90) received within the pass through element(94) can be placed in fixed relation to the cylindrical cup (91) byrotational engagement of the spirally threaded body (92).

Now referring primarily to FIG. 33, as a further non-limiting example,each of a pair of sacroiliac joints (1) can receive an embodiment of thesacroiliac joint implants (6), above-described, each having a couplingelement (87) coupled to the first end (11). Each of the couplingelements (87) can receive the opposed ends (95) of a spanning member(90). Additionally, the spanning member (90) in fixed relation to thesacroiliac joint implants (6) can be connected to a plurality ofadditional spanning members (96) which can as a non-limiting example beplaced in positional relation to the vertebral column (97) to allowsupport of additional implants which can be anchored between vertebrae.

Now referring primarily to FIG. 34, as a further non-limiting example, afirst coupling element (87) can be joined to the first end (11) of anembodiment of a sacroiliac joint implant (6) as above described and thefastener portion (88) of a second coupling element (87) can be disposeddirectly into the bone of the sacrum (4) or the ilium (5), or both. Theopposed ends (95) of a spanning element (90) in the form of a flat platecan be can provide apertures (96) through which the fastener portion(88) of the coupling element (87) can pass. The corresponding parts ofthe external surface of the coupling portion (89) and the spanningmember (90) can be engaged to fix the location of the spanning member(90) allowing for coupling of the lumbar spine to the stabilized pelvisby a plurality of fixation elements to further increase stability.

The method can further employ the use of intraoperativeneurophysiological monitoring to reduce the risk to the patient ofiatrogenic damage to the nervous system, particularly the peripheralnerves, or to provide functional guidance to the surgeon.

EXAMPLE 1

An embodiment of the inventive sacroiliac joint implant having aconfiguration substantially as shown by FIGS. 3-6 and as above-describedwas inserted into a patient under direct visualization and with assistedlateral fluoroscopy. The procedure was performed for the purpose ofassessing in an actual reduction to practice the ability of theinventive sacroiliac joint implant to be safely implanted betweeninferior or caudal portion the articular surfaces of the sacroiliacjoint substantially as shown in FIG. 25 to confirm the that implantationof the sacroiliac joint implant into a implant receiving spaceconfigured substantially as above-described acts to immobilize thesacroiliac joint. The sacroiliac joint implant as above-describedimplanted into the inferior (caudal) portion of the sacroiliac jointproved to immediately immobilize the sacroiliac joint.

As can be easily understood from the foregoing, the basic concepts ofthe present invention may be embodied in a variety of ways. Theinvention involves numerous and varied embodiments of sacroiliac jointfusion system which includes sacroiliac joint implants and methods ofimplanting the sacroiliac joint implants including the best mode toprovide fixation and fusion of the sacroiliac joint.

As such, the particular embodiments or elements of the inventiondisclosed by the description or shown in the figures or tablesaccompanying this application are not intended to be limiting, butrather exemplary of the numerous and varied embodiments genericallyencompassed by the invention or equivalents encompassed with respect toany particular element thereof. In addition, the specific description ofa single embodiment or element of the invention may not explicitlydescribe all embodiments or elements possible; many alternatives areimplicitly disclosed by the description and figures.

It should be understood that each element of an apparatus or each stepof a method may be described by an apparatus term or method term. Suchterms can be substituted where desired to make explicit the implicitlybroad coverage to which this invention is entitled. As but one example,it should be understood that all steps of a method may be disclosed asan action, a means for taking that action, or as an element which causesthat action. Similarly, each element of an apparatus may be disclosed asthe physical element or the action which that physical elementfacilitates. As but one example, the disclosure of “an implant” shouldbe understood to encompass disclosure of the act of “implanting”—whetherexplicitly discussed or not—and, conversely, were there effectivelydisclosure of the act of “implanting”, such a disclosure should beunderstood to encompass disclosure of “an implant” and even a “means forimplanting a member.” Such alternative terms for each element or stepare to be understood to be explicitly included in the description.

In addition, as to each term used it should be understood that unlessits utilization in this application is inconsistent with suchinterpretation, common dictionary definitions should be understood toincluded in the description for each term as contained in the RandomHouse Webster's Unabridged Dictionary, second edition, each definitionhereby incorporated by reference.

For the purposes of the present invention, ranges may be expressedherein as from “about” one particular value to “about” anotherparticular value. When such a range is expressed, another embodimentincludes from the one particular value to the other particular value.Similarly, when values are expressed as approximations, by use of theantecedent “about,” it will be understood that the particular valueforms another embodiment. It will be further understood that theendpoints of each of the ranges are significant both in relation to theother endpoint, and independently of the other endpoint. Moreover, theterm “about” means as to any numeric value a deviation about thatnumeric value of up to ten percent.

Moreover, for the purposes of the present invention, the term “a” or“an” entity refers to one or more of that entity; for example, “amember” or “an elongate member” refers to one or more member(s) or atleast one member. As such, the terms “a” or “an”, “one or more” and “atleast one” can be used interchangeably herein.

Thus, the applicant(s) should be understood to claim at least: i) thesacroiliac joint implants as herein disclosed and described, ii) therelated methods disclosed and described, iii) similar, equivalent, andeven implicit variations of each of these devices and methods, iv) thosealternative embodiments which accomplish each of the functions shown,disclosed, or described, v) those alternative designs and methods whichaccomplish each of the functions shown as are implicit to accomplishthat which is disclosed and described, vi) each feature, component, andstep shown as separate and independent inventions, vii) the applicationsenhanced by the various systems or components disclosed, viii) theresulting products produced by such systems or components, ix) methodsand apparatuses substantially as described hereinbefore and withreference to any of the accompanying examples, x) the variouscombinations and permutations of each of the previous elementsdisclosed.

The background section of this patent application provides a statementof the field of endeavor to which the invention pertains. This sectionmay also incorporate or contain paraphrasing of certain United Statespatents, patent applications, publications, or subject matter of theclaimed invention useful in relating information, problems, or concernsabout the state of technology to which the invention is drawn toward. Itis not intended that any United States patent, patent application,publication, statement or other information cited or incorporated hereinbe interpreted, construed or deemed to be admitted as prior art withrespect to the invention.

The claims set forth in this specification, if any, are herebyincorporated by reference as part of this description of the invention,and the applicant expressly reserves the right to use all of or aportion of such incorporated content of such claims as additionaldescription to support any of or all of the claims or any element orcomponent thereof, and the applicant further expressly reserves theright to move any portion of or all of the incorporated content of suchclaims or any element or component thereof from the description into theclaims or vice-versa as necessary to define the matter for whichprotection is sought by this application or by any subsequentapplication or continuation, division, or continuation-in-partapplication thereof, or to obtain any benefit of, reduction in feespursuant to, or to comply with the patent laws, rules, or regulations ofany country or treaty, and such content incorporated by reference shallsurvive during the entire pendency of this application including anysubsequent continuation, division, or continuation-in-part applicationthereof or any reissue or extension thereon.

The claims set forth in this specification, if any, are further intendedto describe the metes and bounds of a limited number of the preferredembodiments of the invention and are not to be construed as the broadestembodiment of the invention or a complete listing of embodiments of theinvention that may be claimed. The applicant does not waive any right todevelop further claims based upon the description set forth above as apart of any continuation, division, or continuation-in-part, or similarapplication.

I claim:
 1. A sacroiliac joint implant adapted for placement in aninterarticular space between articular surfaces within an articularregion of a sacroiliac joint, the implant comprising: an elongate bodycomprising a first longitudinal axis; a first and a second wing memberextending radially from the first longitudinal axis of the elongatebody, the second wing member disposed in substantially opposed relationto the first wing member, the first and the second wing members forminga first plane; a third and a fourth wing member extending radially fromthe first longitudinal axis of the elongate body, the third wing memberdisposed in substantially opposed relation to the fourth wing member,the third and the fourth wing members forming a second plane, whereinthe second plane is disposed in a substantially orthogonal relation tothe first plane, the first, the second, the third, and the fourth wingmembers generally extend along the first longitudinal axis of theelongate body; and a first bore through the sacroiliac joint implant,wherein the first bore comprises a second longitudinal axis that isgenerally transverse to the first longitudinal axis of the elongatebody, wherein the second longitudinal axis is disposed in a third plane,wherein the third plane is disposed in the proximity of and parallel tothe second plane.
 2. The sacroiliac joint implant of claim 1, whereinthe elongate body is cylindrical.
 3. The sacroiliac joint implant ofclaim 1, wherein the first and the second wing members extend a firstheight radially from the first longitudinal axis of the elongate body,and the third and the fourth wing members extend a second heightradially from the first longitudinal axis of the elongate body, whereinthe first height exceeds the second height.
 4. The sacroiliac jointimplant of claim 1, wherein the first and second wing members comprise afirst width, and the third and the fourth wing members comprise a secondwidth, wherein the first width exceeds the second width.
 5. Thesacroiliac joint implant of claim 1, wherein the elongated bodycomprises a first distal end and a second proximal end, wherein thefirst distal end comprises a bullnose shape.
 6. The sacroiliac jointimplant of claim 1, wherein the first bore extends through the elongatebody.
 7. The sacroiliac joint implant of claim 1, wherein the secondlongitudinal axis is not perpendicular to the first longitudinal axis ofthe elongate body.
 8. The sacroiliac joint implant of claim 1, furthercomprising an anchoring element, wherein the anchoring element isreceived by the first bore.
 9. The sacroiliac joint implant of claim 8,wherein the anchoring element comprises a bone screw.
 10. The sacroiliacjoint implant of claim 1, further comprising a second bore, wherein thesecond bore has a third longitudinal axis parallel with the firstlongitudinal axis of the elongated body.
 11. The sacroiliac jointimplant of claim 10, wherein the second bore is threaded and configuredto fixedly mate with an insertion tool.
 12. The sacroiliac joint implantof claim 10, wherein the second bore further comprises: a second distalend disposed along the first longitudinal axis at about an intersectionof the first and the second bores; and a second proximal end disposedalong the first longitudinal axis at the first proximal end of theelongate body.
 13. The sacroiliac joint implant of claim 1, furthercomprising one or more aperture elements which communicate through oneor more of the first, the second, the third, or the fourth wing membersor elongate body.
 14. The sacroiliac joint implant of claim 13, furthercomprising an amount of biocompatible material located within one ormore of the aperture elements, wherein the biocompatible materialpromotes bone growth.
 15. The sacroiliac joint implant of claim 1,further comprising a coating coupled to at least a portion of at leastone of the elongated body, the first, the second, the third, or thefourth wing members capable of biocompatible osseointegration with theinterarticular surfaces of the sacroiliac joint.